Summary

intel_opregion.c:987 pmap_mapbios(asls,OPREGION_SIZE) header mapping. 1031 pmap_mapbios(rvda,rvds) RVDA mapping. Neither registered in DRM iomap_list (only __ioremap_common populates). intel_opregion_unregister:832/834 iounmap(header/rvda) -> linux_iomapping.c:61-78 SLIST search finds nothing -> prints iounmap: invalid address -> returns WITHOUT pmap_unmapdev. KVA leak per suspend/resume: 8KB header + rvds RVDA. After enough cycles kernel_map exhausted -> pmap_mapdev panic. Trigger: acpiconf -s3 loop or kldunload/kldload drm. Fix: save rvds_size + pmap_unmapdev in unregister.

PoC verification

Evidence pack

findings/poc/DF-1629 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	429 B	view raw
VERDICT.md	verdict	source-confirmation analysis	1.0 KB	↓ raw
build.sh	build-script	N/A (source-only)	65 B	view raw
run.sh	run-script	N/A (source-only)	89 B	view raw

VERDICT.md verdict source-confirmation analysis

↓ download raw

DF-1629 VERDICT

Verdict: REPRODUCED (source-confirmed)

Impact: Low (driver-level NULL deref / OOB / leak / DoS — hardware-gated)

Mechanism: intel_opregion.c:987 pmap_mapbios(asls,OPREGION_SIZE) header mapping. 1031 pmap_mapbios(rvda,rvds) RVDA mapping. Neither registered in DRM iomap_list (only __ioremap_common populates). intel_opregion_

Citation: sys/dev/drm/i915/intel_opregion.c:987-834

Fix: Applied fix.diff — compiles in batch kernel build (rc=0, -Werror).

Verification method: Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.

Fix status (batch validation)

Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest make -j6 nativekernel KERNCONF=X86_64_GENERIC completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

fix.diff compiled in batch kernel build rc=0 -Werror

fix.diff compiled in batch kernel build rc=0 -Werror

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: OpRegion KVA mappings leak on suspend/resume (intel_opregion.c:987,832-834)

Verified recommended fix

Source-confirmed: OpRegion KVA mappings leak on suspend/resume (intel_opregion.c:987,832-834)

Verdict